1. Field of the Invention
The present invention relates to a reverse opening type slide fastener which can be opened upward and in a reverse direction while it is separable and engageable.
2. Background of the Invention
As a slide fastener for opening or closing right and left front bodies of clothes, a separable/engageable type slide fastener having a box pin and an insert pin on the bottom of element rows has been used.
In an ordinary slide fastener having the separable bottom end stop, the insert pin is formed at the bottom end of an element row on one side, while a box into which the insert pin is to be inserted is provided fixedly via a box pin and consecutively from the bottom end of the element row on the other side. Such a slide fastener having the separable bottom end stop is so configured that when a slider is lowered to the lowest position where the slider makes contact with the box, the insert pin can be removed from or inserted into the box and slider, so that right and left fastener stringers can be separated.
U.S. Pat. No. 2,157,381 has described an invention about the ordinary separable bottom end stop for the slide fastener, aiming at suppressing a free sliding of its slider over elements when the insert pin is removed from the slider.
The separable bottom end stop described in U.S. Pat. No. 2,157,381 has a box pin at the bottom end of an element row of a first fastener stringer while a box into which the insert pin provided consecutively from the bottom end of the element row of a second fastener stringer is to be inserted is fixed to the same box pin. The element row of the first fastener stringer has a single slider, which renders the right and left element rows of the slide fastener into a coupling state or in a separated state when the slider is slid passing over the both element rows.
The box pin of the separable bottom end stop described in U.S. Pat. No. 2,157,381 has a projection for suppressing the free sliding of the slider on each of both front and rear side faces opposite to a flange inner face of the slider when the projection engages a recess portion (notch) formed in the flange inner face of the slider.
When a wearer couples both fastener stringers from a state in which they are separate, sometimes, the wearer bends a bottom portion of the element row forward as seen from the wearer in order to facilitate an insertion action for the insert pin into an opening of the slider, so that the bottom portion is lifted up to a position where it is visible easily from the wearer and then, inserts the insert pin into the opening of the slider. Particularly, this method is often applied if the separable bottom end stop is attached to the bottom end of long clothes such that its bottom end is extended to the vicinity of his or her foot.
When the bottom end of the element row is lifted up in a forward bent state, the up-down relation of the slide fastener is reversed at the bottom end thereof, so that the box is located up while the slider is located down. Consequently, the slider may go down in a direction of separating from the box pin due to its gravity. If the slider leaves the box pin, the insert pin which the wearer attempts to insert interferes with the element row leading to the box pin, thereby producing such an inconvenience that the insert pin cannot be inserted. According to a slide fastener described in U.S. Pat. No. 2,157,381, a projection formed on the front and rear side faces of the box pin engages a recess portion formed in the flange inner face of the slider, so as to prevent the slider from separating from the box.
Japanese Patent Application Laid-Open publication No. 2005-245859 has proposed a separable bottom end stop for reverse opening type slide fastener which can be opened in both ways from upward and downward by disposing two sliders such that their rear mouths are opposite to each other.
The reverse opening type slide fastener described in Japanese Patent Application Laid-Open publication No. 2005-245859 has an upper slider and a lower slider which enable the slider to be opened/closed in both ways from upward and downward, and the insert pin which can be removed from and inserted into the upper slider and the lower slider is attached on the bottom end of the element row on one side such that the rear mouths of the upper slider and the lower slider keep contact with each other in the opposite state. Further, a box pin in which an escape preventing stopper is formed in order to lock the lower slider at a lowest position is mounted on the bottom end of the element row on the other side.
An operation of the reverse opening type slide fastener having a separable bottom end stop described in Japanese Patent Application Laid-Open publication No. 2005-245859 in case where the slide fastener is used for opening/closing the right and left front bodies of clothes will be described. If the upper slider is slid downward with right and left fastener stringers completely coupled with each other, the right and left front bodies of clothes can be opened at the top. Further, if the lower slider is slid from down to up together with the upper slider with the slide fastener opened, the right and left front bodies can be opened at the bottom.
When the wearer takes off clothes, the rear mouths of the upper slider and the lower slider are brought into contact with each other in an opposite state and then, lowered to the lowest position. Then, an operation of removing the insert pin attached on the bottom end of the element row from the upper slider and the lower slider is carried out. Consequently, the right and left fastener stringers are separated, so that the right and left front bodies of clothes are separated and the clothes are easy to take off.
To remove the insert pin from the upper slider and the lower slider, the right and left element rows need to be completely kept uncoupled. For that purpose, with the rear mouths of the upper slider and the lower slider kept into contact in the opposite state, the rear mouths need to be kept lowered to the bottom end of the fastener stringer.
When the wearer puts on clothes, the insert pin needs to be inserted into the opening in the upper slider and the lower slider in order to couple separated right and left element rows with each other. In this case, unless the rear mouths of the upper slider and the lower slider are kept in contact with each other in the opposite state and kept lowered to the bottom end of the fastener stringer, the inserted insert pin interferes with the element row, thereby making difficult the insertion of the insert pin.
Further, when the wearer attempts to insert the insert pin with the lower portion of the element row bent forward as seen from the wearer so that the lower portion is lifted up to a position where it can be seen easily by the wearer, the upper slider independently or both the upper and lower sliders may be lowered in a direction of separating from the box pin due to the gravity in many cases. Particularly, if the upper slider leaves the box pin in a separated state, the stringer is bent between the respective sliders. In this case, when the wearer attempts to insert the insert pin, the insert pin cannot be inserted all at once. Consequently, the sliders interfere with the element rows consecutive from the box pin, thereby producing such an inconvenience of complicating the inserting operation for the insert pin.